1. Field
Apparatuses and methods consistent with the present disclosure relate to energy harvesting devices.
2. Description of the Related Art
Energy harvesting technologies are technologies for converting energy, such as vibrations, heat, light, radio frequency (RF), or the like, from the surrounding environment into electric energy by using a converting device. The efficiency of harvesting electric energy has continuously increased along with the developments of the structures and performances of energy harvesting devices. Furthermore, as the voltages and currents for driving semiconductor devices have decreased, electronic devices capable of performing various functions with reduced power consumption have been commercialized. Therefore, energy harvesting technologies may be used for many applications.
Energy harvesting technologies utilizing thermal energy may be used in environments where thermal energy is generated by a fixed heat source. For example, such technologies may be applied to health-care devices using the body temperature or small electronic devices, such as cellular phones, which generate heat. Furthermore, energy harvesting technologies may utilize waste heat from a power plant, heat generated by heating apparatuses in a household or a commercial building, or a temperature difference between the front and rear surfaces of a light collecting panel of a solar battery.
Temperature differences are generally converted into electric energy via thermoelectricity. In the case of using a thermoelectric material for generating a voltage V via a temperature difference ΔT between two opposite ends, electric energy may be obtained from the body temperature or waste heat. However, methods utilizing thermoelectricity have generally low efficiency.